This invention relates to sewing machines and, more particularly, to electronically controlled sewing machines.
Sewing machines employing sophisticated electronic technology for the storage and subsequent retrieval of stitch pattern information for a multiplicity of patterns have enjoyed great commercial success in recent years. One great advantage of the use of an electronically controlled sewing machine is in its simplicity of operation and control, as perceived by the user. With the recent availability of relatively low cost microcomputers, electronically controlled sewing machines incorporating such a device have greatly increased the versatility of control afforded to the sewing machine operator. Accordingly, sewing machine designers increasingly strive to improve the versatility of the sewing machine while at the same time attempting to keep the number of operator manipulatable control elements to a minimum, so that the operator perceives the use of the machine as relatively simple in nature.
One manner of improving the versatility of such a sewing machine is to increase the number and type of patterns which may be sewn by the sewing machine. One type of pattern which it would be desirable to provide for the user's selection is what is termed an extended bight width pattern. Such a pattern is one which may be of arbitrary dimension in the direction lateral to the direction of fabric feeding and is accomplished by means of needle shifting. Needle shifting is accomplished by laterally jogging the needle when the needle is engaged with the work material, as disclosed for example, in U.S. Pat. Nos. 4,123,981 and 4,135,462.
A problem that may arise when sewing an extended bight width pattern is that needle shifting of the work material may catch the operator unaware, causing the operator to lose control of the work material, which may result in a distortion of the pattern being sewn.
It is therefore an object of this invention to provide an arrangement whereby an operator is informed of an impending needle shift.